1. Discussion Comparative analysis between visual observations of each dye series and the optical micrographs suggest that the optimal amount of dye solution added at a concentration near saturation is approximately 100-200 μL. This can be seen by the successful dyed particle suspensions of the tubes labeled (B) in each dye series. Analysis of the dark-field optical micrographs showed that the dye solution did dye the particles the intended color. Although, after analysis of the fluorescent illuminated micrographs, the yellow particles did not fluoresce, while the blue and red particles did fluoresce. The next step would be to perform the experiment and optimize the procedure for additional dyes. The yellow particles demonstrate the desired results of intensely colored yet non-fluorescent particles, which will allow the particle to be fluorescently tagged in future experiments. Additional studies will be done to understand reasons to why the blue and red particles fluoresce. After the proper procedure for each dye is determined, the particles will then be suspended and observed in solution together for efficiently of particle distribution, size, and color differentiation. After the procedure for large dye batches are successfully determined, experiments will be performed related to fluorescently tagging dyed polystyrene particles with protein biomarkers for diseases. Abstract Even though we live in a world characterized by perpetual medical and technological advances, 8 out of every 10 people worldwide lack the ability to have their health problems diagnosed and often suffer and die even though cures to their illness are known. The fundamental research discussed here targets the preliminary development of a color coded colloidal particle library to be used later in bio-affinity arrays capable of multiplex immunoassays where they will be fluorescently tagged to a certain protein so they can be used to diagnosis of a disease. To fully accomplish this goal the most efficient procedures need to be made for the dye solutions used to color the particles and method to dye the particles, so dyed, non-fluorescent, polystyrene (PS) particles can be obtained. Experimental To develop the color-coded, polystyrene particles, appropriate dye solutions had to be prepared. Oil based solvent dyes were used to ensure only the PS particle will be dyed. To prepare the dye solution, dichloromethane was used as the solvent. Surfactant was added to the dye solution and pre-dyed batch of PS particles before mixing. Optimization experiments were conducted to darken the shade of the color in the particles, which was accomplished by adding more dye solution to the particle. Generation of a Color Coded Particle Library for use in Multiplex Immunoassays Kelvin Smith, Dr. Matthew Ray, University of Wisconsin-Stout References Zhao, X., Zhou, S., Chen, M., Wu, L. and Gu, G. (2011), Encapsulation of hydrophilic dyes with polystyrene using double miniemulsion technique. J. Appl. Polym. Sci., 119: 3615–3622. doi: 10.1002/app.33049. Jung-Hyun Lee, Ismael J. Gomez, Valerie B. Sitterle, J. Carson Meredith, Dye-labeled polystyrene latex microspheres prepared via a combined swelling-diffusion technique, Journal of Colloid and Interface Science, Volume 363, Issue 1, 1 November 2011, Pages 137-144, 0021-9797. Mehrpouyan, M.; Recktenwald, D. J.; Varro, R. Multiplex Microparticle System. U.S. Patent 7,507,588, Mar. 24,2009. Chandler, D.J.; Chandler, V.S.; Lambert, B.A.; Reber, J.J; Phipps, S.L. Precision Fluorescently Dyed Polymeric Microparticles and Methods of Making and using same. U.S. Patent 7,445,844, Nov. 4,2008. Banerjee, S.; Gorgescu, C.; Daniels, E.S.; Dimonie, V.L.; Seul, M. Production of Dyed Polymer Microparticles. U.S. Patent 6,964,747, Nov. 15, 2005. Shih, Y.; El-Aasser, M.S.; Vanderhoff, J.W. Colored Latexes; Methods for making same and Colored Finely Divided Products. U.S. Patent 4,487,855, Dec.11,1984. Results The results of the synthesis of the dye series produce the images seen below: KS120114: PS particles dyed with Nile Blue KS120110: Polystyrene Particles dyed with Oil Yellow 2635 dye KS120116: PS particles dyed with Solvent Red 195 Left: Dark field optical micrograph of polystyrene particles dyed with Oil Yellow 2635 dye. Right: Same sample under fluorescence illumination Left: Dark field optical micrograph of polystyrene particles dyed with Nile blue. Right: Same sample under fluorescence illumination Left: Dark field optical micrograph of polystyrene particles dyed with Solvent Red 195. Right: Same sample under fluorescence illumination Conclusions The data show that the dying procedure was successful for preparing color coded polystyrene microparticles with the solvent dyes. Additional experiments need to be performed to select dyes that are highly colored but that do not fluoresce under ultraviolet light. These conditions have been met for the yellow particles presented here, but the procedure will need to be optimized for other dye colors. Dye Name Tube Label Particle Volume Dye Volume Solvent Volume Surfactant Volume Oil Yellow 2635 50 μL 300 μL4.5 g50 μL 400 μL4.5 g50 μL 500 μL4.5 g50 μL 600 μL4.5 g50 μL 700 μL4.5 g50 μL Nile Blue 50 μL 4.5 g50 μL 100 μL4.5 g50 μL 300 μL4.5 g50 μL 500 μL4.5 g50 μL 1000 μL4.5 g50 μL Solvent Red 195 50 μL 4.5g50 μL 100 μL4.5 g50 μL 300 μL4.5 g50 μL 500 μL4.5 g50 μL 1000 μL4.5 g50 μL Dark field micrograph of mixed particle sample